The present invention relates to a billing system for use in printing machines, in particular, printing machines interconnected to multiple stations on a network.
The prior art is replete with methods for obtaining billing information. For example, U.S. Pat. No. 3,974,363 discloses a programmable billing system for use in a stand alone reproduction machine. It provides a means for counting reoccurring events and generating a weighted output value proportional to the billing value of the events. It is also known, as disclosed in U.S. Pat. No. 4,496,237, assigned to the same assignee as the present invention, to store in non-volatile memory indications of machine consumable usage and to be able to display indications of such usage. Further, U.S. Pat. No. 5,305,199, assigned to the same assignee as the present invention, discloses a single tracking system for monitoring inventories of supplies consumed by a network of reprographic machines.
A difficulty with the above described techniques is that there are generally no restrictions on printer usage in a system of multiple workstations or users interconnected to a printer over a network. Another difficulty is the lack of a technique to charge individuals or groups of individuals for usage of printers on the network.
It is an object of the present invention, therefore, to be able to selectively bill individuals or groups of individuals for network usage of printers. It is still another object of the present invention to provide a technique to restrict usage of a printer on a network to legitimate users. Still another object of the present invention is to allocate credit for individual use of a printer on a network, Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.